First Light Curve from Antarctica PAIX Monitoring of the Blazhko Stars

Abstract

PAIX (Photometer AntarctIca eXtinction) is an extended programme monitoring the Blazhko circumpolar stars from one of the highest Antarctica plateau, Dome C (3300 m), using a multi‐color photometer attached at the focus of a 40 cm Ritchey‐Chretien telescope installed during the polar summer 2006. Several high quality RRLyrae light curves are obtained with a quasi‐uninterrupted time coverage over several pulsation and Blazhko cycles. Here, we present the first time series photometry from Dome C obtained on S Ara and during the 2007 polar night, from June to August 2007. Our results show that S Arae is “bona fide” a Blazhko star with strong nonlinearity and triplet structure. New phenomenological descriptions of the light curve variation are reported giving new insight for future Blazhko theoretical investigations and a unique opportunity to cope with the hydrodynamical challenge in connection with the radial pulsation. We conclude that high‐precision CCD photometry with exceptional time coverage can be undertaken at Dome C in order to successfully gain an understanding of the Blazhko effect.